001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.broker.region;
018
019/**
020 * Queue specific MessageReference.
021 * 
022 * @author fateev@amazon.com
023 * 
024 */
025public interface QueueMessageReference extends MessageReference {
026
027    QueueMessageReference NULL_MESSAGE = new NullMessageReference();
028
029    boolean isAcked();
030    
031    void setAcked(boolean b);
032    
033    void drop();
034 
035    boolean isDropped();
036        
037    boolean lock(LockOwner subscription);
038    
039    boolean unlock();
040    
041    LockOwner getLockOwner();
042}